The most common current methods of handling polluted soils and industrial wastes are sewage treatment plants and landfills. These current methods focus on making the soils and wastes environmentally safe. Yet both landfills and sewage treatment facilities have problems. Landfills and treatment facilities are very expensive and generally have serious limitations regarding the handling of toxic wastes. In addition, many communities are placing space limitations and other restrictions on landfills and sewage treatment plants. As the adverse environmental effects of pollutants are recognized, safety regulations are more stringently limiting treatment plants and landfills from permitting the further accumulation of polluted soils and industrial wastes without treatment.
The present invention contemplates treating solid refuse such as polluted soils and industrial wastes to obtain useful materials which need not be disposed of in landfills and treatment plants. The products of the treatment may be used as materials for making cement, or materials for use with cement and materials for use in construction.
The manufacture of cement requires large quantities of low cost raw materials. For economic reasons, cement plants need raw materials that are located nearby. But some cement plants are running out of traditional sources of readily-available and conveniently-located raw materials.
Sand, clay and other minerals in soils are used as raw materials in the manufacture of cement. Sand is also used with cement as an aggregate to make mortar or concrete. In addition, soil free of impurities is used with portland cement as a base for roads.
The present invention enables traditional sources of raw materials to be replaced by raw materials obtained from soils polluted from contact with gasoline or other chemicals. Another potential source of replacement raw materials is industrial waste. Suitable industrial wastes include used filter cake and deionization and demineralization resins.